Seeds of maize (cv. SC AR68) were divided into three sub-samples, one of which was kept as high vigor seed lot (A1) and two others were artificially aged. Each seed sample was then divided into four sub-samples, one of which was not primed and the other three samples were primed in distilled water for 7, 14 and 21 h, and then dried back to initial moisture content. The field experiment was laid out as factorial based on RCB design with three replications. Plant height, ear length, ear diameter and grains per ear of plants from aged seeds were decreased by seed aging, leading to significant reduction in grain yield per unit area. However, these traits particularly plant height and ear length were enhanced by hydro-priming of seeds for 21 h, improving grain yield of maize by about 32%. These results suggest that hydro-priming for 21 h is a useful technique for repairing seed aging and improving plant morphology and grain yield of maize.